Conditional Cell-Penetrating Peptide Exposure as Selective Nanoparticle Uptake Signal

Area of Science:

• Biotechnology
• Nanomedicine
• Drug Delivery

Background:

• Therapeutic efficacy is limited by low drug concentration at the target site.
• Nanoparticles (NPs) with cell-targeting ligands improve drug delivery but can trigger unwanted signaling.
• Cell-penetrating peptides (CPPs) facilitate NP uptake but lack specificity.

Purpose of the Study:

• To develop a receptor-independent method for conditional nanoparticle (NP) uptake.
• To achieve targeted NP internalization exclusively into specific cell types.
• To overcome the limitations of non-specific CPP-mediated NP delivery.

Main Methods:

• Synthesized core-shell NPs using poly(lactide-co-glycolide) (PLGA) and PLA-PEG block copolymers.
• Modified NPs with cell-penetrating peptides (CPPs) and an ACE2 inhibitor (MLN-4760).
• Investigated NP stability, zeta potential, and uptake characteristics in ACE2-expressing cells.

Main Results:

• Identified TAT47-57 (TAT) as a promising CPP for NP modification.
• Developed a system where PEG length and MLN-4760 binding conditionally expose CPPs.
• Achieved an 18-fold increase in NP uptake in ACE2-positive cells compared to unmodified NPs.

Conclusions:

• Demonstrated a conditional, receptor-independent NP uptake strategy.
• This approach enhances selectivity and avoids receptor-mediated side effects.
• Paves the way for improved targeted nanomedicine delivery systems.